Machine for filling and sealing containers

ABSTRACT

A packaging machine for filling and sealing receptacles, the machine having a plurality of stations at which packaging operations are performed by packaging devices ( 21-29 ), the stations having at least a filling station ( 21 ) and a sealing station ( 23, 24, 27 ). The packaging machine includes a conveyor ( 10 ) for causing the receptacles to travel along a path passing through the various stations, the packaging machine being characterized in that the stations are disposed in an enclosure ( 2 ) in which a vacuum prevails.

The present invention relates to a method and a machine for filling andsealing receptacles such as flexible tubes or rigid reservoirs equippedwith fluid dispensers. The machine defined by the invention is thusapplicable to the field of packaging fluids in general, and moreparticularly cosmetics or pharmaceuticals such as creams, lotions, oreven more-watery liquids.

The industrial sectors of pharmaceuticals and of cosmetics, amongothers, produce many delicate fluids that require very good qualitypackaging. Certain fluids are sensitive or even reactive to air, tolight, to humidity, etc. It is therefore necessary for the packaging ofsuch fluids to protect them from such damaging environments.

A technique that is in wide use for fluids that are not too sensitiveconsists in providing the reservoir containing said fluid with an“airless” dispenser device, i.e. a dispenser device that has no airintake: as the fluid is dispensed, the volume of the reservoir decreasescorrespondingly so that the fluid is never in contact with air insidethe reservoir. That type of dispenser device is in common use for fluidsthat tend to oxidize.

In the field of vacuum packaging, mention may be made of Document GB 246347 which describes vacuum canning apparatus. That apparatus is providedwith an inlet via which non-sealed filled cans are inserted. The cansfollow a circular path on a rotary carrousel. Over a portion of therotary path, the cans are subjected to a gradually increasing vacuum.The manner in which the vacuum sealed cans are removed from thecarrousel to bring them back to ambient pressure is not described. Theobject of that apparatus is to seal cans under a vacuum without anysudden variation in pressure, which would disturb the contents of thestill-open cans and thus cause said contents to be spilled. The problemof packaging delicate fluids is not addressed since the cans are filledat ambient pressure outside the apparatus.

Mention may also be made of Document U.S. Pat. No. 5,481,851 whichdescribes apparatus for canning waste. In that apparatus, empty cans areinserted into a rotary carrousel via an inlet. The cans pass throughvarious stations in which they are purged with nitrogen, they are filledwith waste, they have their air evacuated from them, they are sealed,and then they are unloaded from the apparatus. Clearly, the cans aresealed in ambient air at the outlet door. The purpose of evacuating theair is not to achieve vacuum sealing, but rather merely to extract theair from the can.

For more sensitive fluids that are difficult to preserve, use is made ofvacuum packaging techniques. The reservoir is sealed in an enclosure inwhich a certain degree of vacuum prevails. This guarantees that thefluid is not packaged in the reservoir together with air, which coulddamage it.

Document U.S. Pat. No. 3,006,120 describes apparatus for evacuating airfrom pouches, and for then filling them with gas and sealing them. Eachpouch is brought into a rotary carrousel provided with sixteenenclosures, each of which serves to receive a respective pouch. Eachenclosure comprises a cup and a lid to which an air evacuation line anda gas filling line are connected. Each lid is also provided with asealing jaw system. There are therefore as many lines and as manysealing systems as there are enclosures, i.e. sixteen air evacuationlines, sixteen gas filling lines, and sixteen sealing systems. It isfurther necessary to break the vacuum in each enclosure for the purposesof removing the filled and sealed pouch, and of inserting a new pouch.That takes time. It should also be noted that the fluid packaged in thepouches, i.e. the gas, is not a delicate fluid, and the only object ofremoving the air is to improve the filling with gas, and not to keep thegas from the air. The filling gas occupies the entire volume of theenclosure so that there is definitely only gas in the pouch when it issealed. That does not apply with liquids.

For very sensitive fluids, it is also necessary to incorporatepreservatives in the fluid in order to improve stability because thefluid may be in contact with air before it is packaged. Addingpreservatives has an impact on the cost of the fluid, and can, for somefluids, cause allergic reactions in the user.

An object of the present invention is to remedy the drawbacks of theprior art by defining a machine for packaging sensitive liquids thatmakes it possible to reduce, or even omit, preservatives. In addition,the machine should be capable of operating at high throughput. It shouldalso be as compact as possible.

To this end, the present invention provides a packaging machine forfilling and sealing receptacles, said machine having a plurality ofstations at which packaging operations are performed by packaging means,the stations comprising at least a filling station and a sealingstation, said machine including conveyor means for causing thereceptacles to travel along a path passing through the various stations,the stations being disposed in an enclosure in which a vacuum prevails.By making provision for the filling and the sealing to be effected in asingle common enclosure in which a vacuum prevails, it is possible toguarantee that the fluid to be packaged is never in contact with theair, so that it cannot be degraded. The fact that the fluid to bepackaged is worked in a continuous vacuum makes it possible to reducethe quantity of preservatives required for its stability. Not only isthe fluid less costly because of the small quantity of addedpreservatives, but also the fluid is purer. Another visible advantageprocured by the invention lies in the fact that the throughput of themachine may be accelerated, since there is no longer any interruption ofthe vacuum during the filling and sealing step.

In addition, since the stations are placed in a common enclosure, all ofthe stations are common to all of the receptacles because they travelfrom one station to another. This does not apply in the device ofDocument U.S. Pat No. 3,006,120 in which each receptacle is placed in anindividual enclosure equipped with packaging stations. Once thereceptacle has been filled and sealed, the enclosure is opened. Thisdoes not apply in the invention, with a single enclosure housing all ofthe stations. The enclosure does not need to be opened under normaloperating conditions.

According to technical characteristics of the invention, the conveyormeans are in the form of a rotary carrousel equipped with a plurality ofreceptacle-receiving means for receiving the receptacles. The pathdescribed by the conveyor means thus forms a loop. In addition, theenclosure includes a vacuum bell which covers said plurality of stationsin airtight manner. Advantageously, the packaging means are secured tothe vacuum bell. In addition, the bell is provided with an insertionairlock for inserting empty receptacles, and with an ejection airlockfor ejecting filled and sealed receptacles.

In one embodiment, the packaging means include hot air sealing meansserving to seal flexible receptacles. This technique of sealing byheating with air is a known technique in packaging fluids in flexiblecasings or tubes. However, a paradoxical characteristic of the presentinvention lies in the fact that such a technique is used in a vacuumenclosure. Whereas other known techniques such as sealing by ultrasound,induction, or heater jaws are more easily imaginable in an enclosure inwhich a vacuum prevails, because they do not use air, the technique usedin the invention goes against the requirements of vacuum sealing becausehot air is forced into the enclosure, which would normally break orweaken the vacuum.

The technique of heating by air is advantageous compared with theabove-mentioned techniques because the mechanism is simpler and makes itpossible to heat only the inside wall of the flexible receptacle. Inaddition, it makes it possible to obtain higher throughputs. With heaterjaws, it is necessary to have three of four pairs of jaws to obtain thesame throughput.

Alternatively or additionally, the packaging means include crimpingmeans for crimping a dispenser device to the neck of a reservoir. Alsoalternatively or additionally, the packaging means includesnap-fastening means for snap-fastening a dispenser device to the neckof a receptacle. Advantageously, the vacuum bell is provided with aninsertion airlock for inserting dispenser devices. The machine of theinvention may comprise a plurality of stations specifically adapted topackaging a plurality of different types of receptacle. To this end, thereceptacle-receiving means may be modulated or interchanged as afunction of the type of receptacle to be received.

The invention is described more fully below with reference to theaccompanying drawing which gives an embodiment of the invention by wayof non-limiting example.

In the drawing, the sole FIGURE shows a multi-purpose packaging machineof the present invention.

The example of the machine chosen to illustrate the present invention isof the multi-purpose type, i.e. it is adapted to packaging both flexibletubes and rigid reservoirs. Conventionally, each flexible tube is filledvia one of its ends which is left open to enable filling to take place.Once the fluid has been inserted into the flexible tube, the end of thetube is sealed in leaktight manner. This operation of sealing the end ofthe tube is generally achieved by heat-sealing. That is why the flexibletubes must be made of a material capable of softening at a relativelylow temperature. In general, the flexible tubes are made of a plasticsmaterial. The rigid reservoirs are generally made of glass or of metal,and the filling operation takes place via the neck of the reservoir. Theoperation of sealing the reservoir is achieved by fixing the chosendispenser device to it. There are various methods of fixing a dispenserdevice to the neck of a rigid reservoir. For example, the dispenserdevice may be crimped or snap-fastened in leaktight manner. The machineshown in the sole FIGURE is thus of a multi-purpose type because it iscapable of handling both of these types of packaging. Naturally, andwithout going beyond the ambit of the invention, it is possible toimagine a machine capable of handling one of the types of packagingonly, i.e. either flexible tubes or rigid receptacles.

The machine proposed by the present invention makes it possible topackage a liquid-to-creamy fluid, and preferably a creamy fluid, in theabove-described types of packaging, from filling to sealing. Accordingto a very advantageous characteristic of the invention, the packagingsteps from filling to sealing take place in an environment in which avacuum prevails. Therefore, the fluid being packaged never comes intocontact with air. In order to keep the fluid isolated from air, it isnecessary to provide the packaging, i.e. the flexible tubes and/or theflexible receptacles, with airless dispenser devices. It is thusguaranteed that the fluid is never in contact with air until it isdispensed by the user.

With reference to the sole FIGURE, it can be seen that the multi-purposepackaging machine in the embodiment shown is cylindrical in overallshape and is made up essentially of two portions, namely a bottomportion forming a base 1 and a top portion formed by a transparent bell2.

The base 1 includes a cylindrical protective outer shell enclosing amotor suitable for generating turning about an axis 20 passing centrallythrough the base and the transparent bell 2. The motor enclosed in thebase 1 is also provided with indexing means that make it possible tostop the turning motion generated by the motor in predeterminedlocations. A turntable 10 is mounted to turn about the axis 20. Theturntable is of annular shape and of size substantially corresponding tothe size of the protective shell of the base 1. Naturally, the axis ofrotation 20 passes through the center of the turntable 10, so that saidturntable is caused to turn about its own axis under drive from themotor. Because of the indexing associated with the motor, the turntable10 is caused to stop after turning through a certain determined angle.The turntable 10 is provided with a plurality of means, in the form ofcups, for receiving flexible tubes or rigid reservoirs. In theembodiment shown in the sole FIGURE, ten cups are provided, designatedby the numerical references 101 to 110. Since there are ten cupsprovided in the example shown, the indexing associated with the motormust be suitable for stopping the turning motion after an angular strokeof 36°. The turntable 10 thus forms an indexed carrousel provided with aplurality of cups for receiving containers (flexible tubes or rigidreceptacles). Each cup 101 to 110 is actuated by a raising and loweringactuator (not shown) situated below the turntable 10 in the base 1.Under the action of its respective actuator, each cup is thus capable ofmoving in vertical translation.

The indexed carrousel formed by the turntable 10 is merely an embodimentof conveyor means suitable for causing the containers to travel.Naturally, it is possible to devise other versions for the conveyormeans, e.g. for conveying the containers along rectilinear conveyorpaths. A circular conveyor path as used in the present description ismerely a preferred embodiment of the conveyor means necessary for thepresent invention. All of the cups can be moved by a single motor and bysingle indexing means.

The base 1 comprises the motor and its turntable 10 equipped with itscups and underlying the cylindrical transparent bell 2 which stands inairtight manner on a peripheral edge 11 of the base 1 so that the baseand the bell together form a vacuum enclosure. For example, a sealinggasket may be interposed between the transparent bell 2 and the base 1.The transparent bell 2 has a cylindrical peripheral wall 2 a and anannular cover 2 b.

The vacuum inside the enclosure is achieved by evacuating the airthrough an evacuation channel 3 connecting the bell 2 to a vacuum pumpcapable of extracting up to 2000 cubic meters (m³) of air per hour. Theair pump must also be capable of evacuating an incoming air flow of afew cubic meters per hour while maintaining a pressure approximately inthe range a few millibars to a few tens of millibars inside theenclosure, for reasons given below. The working pressure of thepackaging machine of the invention thus lies in the pressure range a fewmillibars to a few tens of millibars, and is preferably ten millibars.At this pressure, it can be considered that the fluid is not in contactwith air.

The indexing of the carrousel 10 is suitable for stopping the turntablefrom turning so that the cups 101 to 110 remain stationary for arelatively short lapse of time at positions in which they co-operatewith respective associated packaging devices or instruments to define aplurality of packaging stations. A cup considered individually, e.g. thecup referenced 101, thus travels over a circular path and stops at eachpackaging station. The angular offsets between the various cups 101 to110 must be strictly equal since each cup must go through all of thepackaging stations.

The packaging instruments, units or devices provided at each packagingstation are mounted on the transparent bell 2, either on its peripheralwall 2 a, or on its cover 2 b. Other packaging instruments, units ordevices are directly included in the transparent bell 2. The devicesprovided on the transparent bell 2 are those which serve to insertsomething into the bell or to extract something therefrom. The otherpackaging devices provided in the bell are those serving to act directlyon the receptacle.

In the order of the packaging sequence, the first packaging device isthe insertion airlock 21 which serves to insert the empty receptaclesinto the transparent bell 2. The airlock 21 is shown diagrammaticallywith its vacuum door 210 which closes off the passageway of thereceptacle. The empty receptacles thus penetrate into the bell throughthis airlock 21, and they are positioned in the successive cups situatedexactly vertically below the insertion airlock 21. This is how thereceptacles are inserted into the transparent bell 2.

As indicated by the circular arrow shown on the base 1, the turntable 10turns clockwise. Thus, the next packaging station corresponds to thepackaging station in which the cup referenced 106 is positioned. Thispackaging station does not need any device fixed on the transparent bell2. It is the packaging station serving to set the angular positions ofthe receptacles as still empty. This angular positioning of thereceptacles takes place simply by turning the cup. Once the receptacleis correctly angularly positioned, the turntable moves once againthrough one tenth of a turn to the next packaging station.

This station includes a filling unit 22 which feeds the fluid from afeed pipe 220. It should be noted that the filling unit is mainlysituated outside the transparent bell 2 on its cover 2 b. Only thefilling tube 221 which penetrates into the receptacle for filling itwith fluid is disposed inside the transparent bell 2. Thus, it is notnecessary to remove the transparent bell from its base 1 to act on themechanism of the filling unit 22. The filling unit 22 may be equippedwith a device for monitoring the fluid level and enabling the fillingtube 221 to rise as the receptacle fills with fluid. Once the receptacleis filled with a sufficient quantity of fluid, the indexed motor of theturntable 10 is activated to bring the cup to the following station.

In the multi-purpose machine used to explain the invention, it ispossible to package both flexible tubes and rigid receptacles. To thisend, the following three packaging stations serve specifically forflexible tubes. Prior to being inserted through the insertion airlock21, the flexible tubes are already equipped with dispenser devices suchas pumps. The end of the flexible tube that is situated at the endopposite from the pump is still open because it is through this open endthat the fluid is inserted. The flexible tubes with their pumps andtheir open ends are inserted through the insertion airlock 21 while theyare upside down, so that the pump is disposed in the cup. The flexibletubes are then conveyed to the filling unit 22 where they are filled.The next three stations, which are described in detail below, serve toseal the end of the flexible tube. The first of these packagingstations, corresponding to the position of the cup 108, is a heater unit23 which serves to heat the open end of the flexible tube in order tosoften it for the purpose of subjecting it to heat-sealing. Thus, oncethe filled flexible tube comes vertically in register with the heaterunit 23, the actuator of the cup is actuated to cause the flexible tubeto rise until its open end is engaged over the heater nozzle of theheater unit. In the invention, the heater unit 23 is a hot air heaterunit suitable for forcing hot air onto the end of the tube so as tosoften it. Paradoxically, air is inserted through the heater unit intothe enclosure in which a vacuum prevails. That is why the vacuum pumpconnected via the vacuum channel 3 must be capable of evacuating anincoming air flow of a few cubic meters per hour. The incoming air flowdelivered through the heater unit is about a few cubic meters per hourat a temperature in the range 270° C. to 300° C. The heater nozzle isfed with filtered ambient air. This means that if the feed air and theair around the machine is sterile or clean, the probability of having aclean vacuum enclosure is higher. The sealing technique used in themulti-purpose machine of the invention, namely air heating, is atechnique that is known in packaging fluids in flexible tubes orcasings. However, while other known techniques such as sealing byinduction, by ultrasound, or by heater jaws are more easy to imagine inan enclosure in which a vacuum prevails, because they do not use air,the technique used in the invention goes against the requirements ofvacuum sealing, given that the hot air is forced into the enclosure,which would normally break or weaken the vacuum. The technique ofheating with air is advantageous compared with the above-mentionedtechniques because the mechanism is even simpler and makes it possibleto heat only the inside wall of the end of the tube. In addition, itmakes it possible to obtain higher throughput. With heater jaws, it isnecessary to have three or four pairs of jaws in order to obtain thesame throughput. The hot air is fed at a flow rate approximately in therange 1 m³ per hour to 12 m³ per hour, and preferably 7 m³ per hour.Once the top end of the end portion of the flexible tube is sufficientlysoftened, which takes a few tenths of a second, the flexible tube isdisplaced to the next packaging station which is equipped with coldsealing jaws 24 suitable for being pressed together with the heated openend nipped between them. This results in the heated open end of the tubebeing applied onto itself so as to achieve heat-sealing. It is thereforeessential for the step of pressing the open end onto itself to beperformed a very short time after the end has been heated at the heaterunit 23. Preferably, to prevent the temperature of the jaws from risingexcessively, and to enable the sealing to take place as quickly aspossible, an internal water cooling circuit is provided for coolingthem. As soon as the end of the flexible tube has been pressed by thecold jaws 24, the flexible tube is sealed.

It is also possible to imagine that the machine can seal flexiblereceptacles of types other than flexible tubes, such as flexiblepouches, flexible casings, etc. This hot air vacuum sealing techniquemay be used to seal all types of flexible receptacles, and it can beimplemented independently of a rotary carrousel.

The next packaging station corresponding to the cup 110 is equipped witha cutting device 25 serving to cut off the tip of the end portion of theflexible tube that is situated beyond the heat seal, for reasons ofpleasing appearance. The offcuts of plastic may be ejected from theenclosure via a volume airlock.

The flexible tube as filled and sealed is then conveyed to its nextpackaging station at which it is extracted from the enclosure via anejection airlock 29. From the station equipped with the cutting device25 to the ejection airlock 29, the flexible tube is not subjected to anyfurther packaging operation, although it stops at and goes on from threestations corresponding to the positions of the cups 101, 102, and 103.The ejection airlock 29 may be an airlock mounted to move inreciprocating manner and equipped with a vacuum door 290.

In the invention, the multi-purpose machine is also adapted to packagingrigid receptacles on which dispenser devices such as pumps may bemounted. The rigid receptacles, which may be made of glass, of metal, orof plastic, are inserted through the insertion airlock 21 while they arenot yet equipped with their pumps. They are positioned in the cups withtheir mouths open upwards. They undergo the same packaging operations asthe above-mentioned flexible tubes until the filling unit 22. They arethus angularly positioned and then filled with the desired fluid. Then,the filled rigid receptacle does not undergo any packaging operation atthe next three stations corresponding to the hot sealing for flexibletubes. The next station at which the rigid receptacle undergoes apackaging operation corresponds to the position of the cup 101. In thisposition, the cup is vertically in register with a pump insertionairlock 26 equipped with a vacuum door 260. The pumps are thus insertedat this airlock 26 and they are positioned on the necks of the filledrigid receptacles.

The filled rigid receptacle then moves on to the next stationcorresponding to the position of the cup 102. The cup is then situatedvertically in register with a crimping or snap-fastening unit 27. As afunction of the technique used to fix the pump on the neck of thereceptacle, either a crimping unit or a snap-fastening unit may beprovided. Regardless of whether the pump is fixed to the neck of thereceptacle by snap-fastening or by crimping, the effect of this fixingis to isolate the fluid inside the receptacle in airtight manner.Whereafter, the fluid contained in the receptacle no longer has anycontact with air until it is dispensed. Advantageously, the crimpingheight and diameter may be set from the outside without stopping themachine.

The next station is equipped with an injection unit for injectingnitrogen or filtered air into the metering chamber of the pump so as toprevent any fluid from being dispensed while the pusher is being fittedto the pump. A full and detailed description of the structures and modesof operation of the crimping or snap-fastening unit and of the gasinjection unit is given in Document EP-0 509 179.

Once it has left the last packaging station 28, the filled receptacle asequipped with its pump fixed in airtight manner is ejected from theenclosure via the ejection airlock 29, which also serves for ejectingthe flexible tubes. To this end, it should be noted that the airlocksystems, which are preferably reciprocating systems, make it possible totake the containers and the pumps from atmospheric pressure to apressure of about 10 millibars without any difficulty and withoutaffecting the vacuum.

The multi-purpose machine of the invention makes it possible firstly tohandle a plurality of different types of receptacle (flexible tubes orrigid receptacles), and secondly to perform filling and sealingoperations under a continuous vacuum. This makes it possible to achievehigh throughput, since it is not necessary to return to atmosphericpressure between each operation. All of the operations follow withoutinterruption in a controlled vacuum atmosphere.

It should also be noted that the units required for inserting orejecting the receptacles, and the units required for filling, heating,crimping or snap-fastening, and injecting gas are mainly situatedoutside the enclosure. Thus, it is possible to act on their mechanismswithout having to remove the transparent bell 2. These units can even beadjusted while the multipurpose machine is operating.

The multi-purpose machine chosen to illustrate the invention constitutesmerely one embodiment of the invention. It is possible to consider amulti-purpose machine that has more or less packaging stations, but inwhich all of the stations work in an enclosure in which a continuousvacuum prevails.

What is claimed is:
 1. A packaging machine for filling and sealingreceptacles, said machine having a plurality of stations at whichpackaging operations are performed by packaging means (21-29), thestations compromising at least filling station (21) and a sealingstation (23, 24, 27), said machine including conveyor means (10) forcausing the receptacles to travel along a path passing through thevarious stations said packaging machine being characterized in that thestations are disposed in an enclosure (2) in which an air vacuum ismaintained.
 2. A machine according to claim 1, in which the conveyormeans (10) are disposed inside the enclosure (2), and they are in theform of a rotary carrousel equipped with a plurality ofreceptacle-receiving means (101-110) for receiving the receptacles.
 3. Amachine according to claim 2, in which the receptacle-receiving means(101-110) may be modulated or interchanged as a function of the type ofreceptacle to be received.
 4. A machine according to claim 1, in whichthe enclosure includes a vacuum bell (2) which covers said plurality ofstations.
 5. A machine according to claim 4, in which the packagingmeans (21-29) are secured to the vacuum bell (2).
 6. A packaging machineaccording to claim 4, in which the bell (2) is provided with aninsertion airlock (24) for inserting empty receptacles, and with anejection airlock (29) for ejecting filled and sealed receptacles.
 7. Amachine according to claim 1, in which the packaging means include hotair sealing means (23) serving to seal flexible receptacles.
 8. Apackaging machine according to claim 1, in which the packaging meansinclude crimping means (27) for crimping a dispenser device to the neckof a reservoir.
 9. A machine according to claim 8, in which theenclosure vacuum bell is provided with an insertion airlock (26) forinserting dispenser devices.
 10. A machine according to claim 1, inwhich the packaging means include snap-fastening means (27) forsnap-fastening a dispenser device to the neck of a receptacle.
 11. Themachine according to claim 1, in which the pressure inside the enclosurewhen the vacuum is maintained is about a few millibars to a few tens ofmillibars.
 12. The machine according to claim 1, in which apharmaceutical or cosmetic is filled in the receptacles.